CARAT - The weight of a diamond is expressed in carats. 1ct =0.2 gram
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| 7.00 |
5.00 |
4.00 |
3.00 |
2.50 |
2.00 |
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| 1.75 |
1.50 |
1.25 |
1.00 |
0.75 |
0.50 |
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| 0.25 |
0.20 |
0.15 |
0.10 |
0.05 |
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COLOUR - Colour is graded by comparison to masterstones under standardized artificial light, equivalent to Northern daylight
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| D |
E |
F |
G |
H |
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| exc. white+ |
exc. white |
rare white+ |
rare white |
white |
| I |
J |
K |
L |
M |
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| slightly tinted white |
slightly tinted white |
tinted white |
tinted white |
tinted colour |
| N-O |
P-R |
S-Z |
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| tinted colour |
tinted colour |
tinted colour |
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CLARITY - A diamond is called 'loupe clean' if, after examination by an experienced grader with a loupe 1Ox under normal light conditions, it has been found free of internal characteristics. The other clarity grades are determined by the size, position, brightness and number of internal characteristics. External characteristics and structure phenomena can be mentioned under 'identification marks' or 'comments'. The lowest clarity grades on the scale (indicated by p for pique) refer to inclusions that can be seen by an experienced grader with the naked eye
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| FL-IF |
WS1-WS2 |
VS1-VS2 |
SI1-SI2 |
I1-I2 |
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CUT - On an HRD certificate, the description of the cut is split into a separate description of the proportions (angles of inclination and proportional relations between the various parts of the stone) and finish, which is mainly concerned with symmetry deviations and the positioning of the facets
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Diameter - The width of the diamond as measured through the girdle
Table - This is the large, flat top facet of a diamond
Crown - The upper portion of a cut gemstone, above the girdle
Girdle - The narrow rim of a diamond that separates the crown from the pavilion. It is the largest diameter to any part of the stone
Pavilion - The lower portion of the diamond, below the girdle. It is sometimes referred to as the base
Culet - The tiny facet on the pointed bottom of the pavilion, which is the portion of a cut gem below the girdle
Depth - The height of a gemstone, from the culet to the table |
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SHAPE - some common diamond shapes
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| Princess |
Oval |
Marquise |
Pear |
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| Heart |
Round Brilliant |
Emerald |
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